Like other areas of the broadcast industry, video backhaul— even HD — cannot escape the long tentacles of the computer industry.
A little more than a week ago, HauteSpot Networks announced a new compact wireless IP bridge that can transmit up to 65Mb/s from 1.25mi away at a price more in line with the computer industry than the broadcast market.
HD Technology Update spoke with Bob Ehlers, CEO of Hautespot Networks, about the company’s HauteRoute HR-IXPSXPi compact wireless bridge, and how it could be used to transmit HD from the field over an IP network.
HD Technology Update: Is the HauteRoute HR-IXPSXPi compact wireless bridge suitable for wireless camera ENG-type applications where HD is being transmitted back to a central remote point for turnaround back to a station?
Bob Ehlers: Yes. There are two approaches. One is IP directly out of the camera. Companies like JVC and Thomson Grass Valley both have cameras now that are putting out motion JPEG (M-JPEG) encoded video directly from the camera to an Ethernet port. So, we can take that IP output directly into one of our bridges.
The other case is where a camera is outputting HD-SDI, SDI, HDMI or other digital formats where that can be plugged into an external encoder, and that can be plugged into one of our bridges.
For instance, we worked with Electrosonic and we’ve tested with XVD Corp. encoders using our bridges underneath them, and we have been able to achieve up to 1080p at 60fps with about 30ms of total latency. That would be the Electronsonic encoders we’ve tested with.
HD Technology Update: Your press release says the wireless bridge uses a range of frequencies in licensed and unlicensed spectrum. Could you be more specific?
Bob Ehlers: In the unlicensed range, we support the 902MHz-928MHz, 2.4GHz and 5GHz. We also support the 4.9GHz public safety band, and then we have licensed applications primarily for government and export use in the L-band, which is 1755MHz-1850MHz, 4.4GHz and 4.8GHz, which are military bands, and we also have 3.3 GHz, 3.4 GHz and 3.6GHz bands for the European use.
HD Technology Update: What frequencies do you expect broadcasters to use here in the United States and what sorts of performance can they expect on those bands?
Bob Ehlers: Most of the broadcasters adopting our products would be using the unlicensed 5GHz band. At that band, they can expect performance up to 65Mb/s for streaming media with extremely low delay variation and jitter. Our wireless protocol is optimized for streaming media such as UDP multicast, MPEG-4, MPEG-2 or M-JPEG. The range they could expect is dependent on the type of antennas they use, but sticking with relatively small omnidirectional antennae, say a 4dB-5dB gain antenna, they can expect a range up to about 1000ft, and that would be a line of sight. Non-line of sight would be somewhere around 500ft at that maximum bit rate.
If they went to a slightly larger antenna — still portable, they can get out to about 2km fairly easily.
HD Technology Update: What strategies can be used to extend that range without using antennas that are too large to be practical?
Bob Ehlers: You can place repeater locations virtually anywhere, because we are using TCP/IP, we have lossless repeating. In other words, we can regenerate that RF signal and move that digital signal without degrading the video image. We’re going to trade off a little bit of latency, but we can extend our link length simply by putting a repeater node in the middle.
HD Technology Update: You envision broadcasters using the wireless bridge in unlicensed bands. How are broadcasters responding to that, especially for critical situations in which they can’t afford to risk being interfered with by other users of the band they are on?
Bob Ehlers: Certainly, when someone is looking at absolute, high-revenue situations, such as in sports broadcast, they would probably take a licensed BAS solution specifically because they want the frequency allocation and they want to make sure the spectrum is clear for their use.
With our technology, we’ve found that even in high (RF) noise environments, such as trade shows, we are able to get all of the performance very reliably. For example, at InfoComm a couple of months ago in Los Angeles, we ran a link between the Electrosonic and Planar booths driving an HD display wall. It was about a 600ft length, and it ran for the three days of the show with an average rate of frame drops of about one frame per hour. So, it was very reliable.
HD Technology Update: Do you have any broadcast-specific examples?
Bob Ehlers: We are starting to get picked up by low-power TV stations, community broadcasters and event production companies. Anywhere that someone doesn’t have the budget to pay for a 2GHz BAS license and the high-end ENG equipment, we are a very economical alternative to those types of systems.
We’ve been picked up by CNBC in Pakistan. They are using it for a studio point-to-point outdoor link. We’ve been used by the CBS affiliate in San Francisco for remote traffic cameras where they have cameras on buildings that are basically fixed positions and backhauling video to their studio.
HD Technology Update: Your system uses TCP/IP protocol. What benefits does TCP/IP bring to broadcast remote applications?
Bob Ehlers: We are fully bidirectional, full duplex TCP/IP. As far as using our equipment and taking full advantage of TCP/IP, broadcasters are moving from being direct-to-consumer broadcasters to where they are becoming content producers. That content is going out on not only terrestrial broadcast, cable and satellite, but it is now going out through the Internet in various forms. Broadcasters are streaming media on a Web site or distributing it out through CDMA and GSM networks — cell phones. That content is IP, and it is being delivered that way.
So, having native encoding at the source makes it much more flexible. You are able to move that data around from the very beginning. If you are tied to proprietary or high bit rate pipes like HD-SDI for moving the data from the camera back to a mixer, and then getting it onto the network, that kind of limits you.
We can put a camera virtually anywhere and use the Internet to backhaul that signal, provided we have a big enough pipe. So, broadcasters can have locations pretty much anywhere on the Internet for backhaul from their camera to the studio.
The other thing that is important is because we have bidirectionality, we can do real-time control of things like our integrated encoder. If we have an encoder and decoder that are intelligent, they can talk to each other and do dynamic rate adjustment and rate adaptation so that if we’re dealing with an unlicensed band and there is some interference or noise, we can bring down our bit rate in order to compensate for that noise, and our encoder can adjust.
COFDM solutions can’t do that. They don’t have the dynamic adjustments and rate adaptation that IP has.
Finally, IP allows us to put other devices out with the camera. We can put a pan-tilt zoom controller; we can put some type of sensors, motion detectors and wind and weather systems out there. We can even use voice over IP so we can send a voice channel back and forth to camera operators on remotes. So, we are really creating a large utility pipe that can be used in lots of different ways.
HD Technology Update: How does your approach compare in terms of cost to traditional broadcast industry solutions?
Bob Ehlers: Our products leverage existing networking technology. We use high-performance TCP/IP network processors. We use some off-the-shelf radio components. We are using software code pulled from the open source community. We are combining all of those elements together to deliver a solution for broadcasters that is an order of magnitude less expensive than a custom-built, ground-up, proprietary design.
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